Japan Digital Design Investigating Crypto Exchange Zaif Hack

Japan Digital Design (JDD), a subsidiary of banking giant MUFG, has claimed to have found the hackers who stole $60 million from Japanese crypto exchange Zaif earlier this year.

Zaif, which is powered by Tech Bureau and one of 16 exchanges licensed by the Japanese government, was originally hacked on September 14, but the security breach was not detected until September 17. The exchange lost 6.7 billion yen ($60M USD) worth of crypto assets belonging to both customers and to the company itself. The compromised funds were denominated in bitcoin (BTC), bitcoin cash (BCH), and monacoin (MONA).

In a press release, JDD said that it has been monitoring the outflow of funds from Zaif since the hack, in collaboration with the CTF team TokyoWesterns and Takayuki Sugiura of the joint company EL Plus. JDD said that since the stolen Monacoin began to be moved from Zaif on October 20, they succeeded in identifying the source of 5 transactions in question and provided information to the authorities concerning the characteristics of the transaction originator.

“In the investigation of the leaked virtual currency, remittance route has been analyzed through static analysis of the block chain, but with this effort, by deploying the virtual currency node on a large scale after the outflow of the virtual currency, we verified whether we can obtain clues such as source IP address etc. We also got useful data to grasp the accuracy of the information and the cost of tracking,” JDD said.

Following the hack, Japan’s Financial Services Agency (FSA) issued a third business improvement order to Tech Bureau, pressing for more details about how the hack actually took place and its response to customers. Last month, Tech Bureau announced that it will start reimbursing users when technology group Fisco takes over the exchange. Fisco will reportedly use its own bitcoin and Bitcoin Cash to refund users who had lost holdings of the two crypto assets. Users who lost Monacoin will be paid back part of their losses in Japanese yen at a rate of 144.548 yen for one coin.